How To: Build a lower arm bar for under $15
 

How To: Build a lower arm bar for under $15

This is a cheap and easy way to get a lower arm bar for your car. This is a brace that spans the gap between the rear pivot points of the a-arms on the front suspension. All the commercial units out there are $100 or more. This shouldn’t cost you more than 10-15 US dollars once it’s done. I got the steel for $5 and the hardware for $5 and I have lots of spray paint lying around the house, so all in all mine cost me a whopping $10 (Canadian Dollars).

NOTE: This may not fit all FC’s as the exhaust might interfere. I’ve got a Racing Beat down pipe on my car (normally aspirated), and it has plenty of clearance. I don’t know if it’ll fit onto turbo FC’s or FC’s with headers, so check your car first! You can see if it’ll fit by seeing if a flat piece of something can go between the inner bolts on the bushing clamps for the rear of the front a-arms.

What this brace is:
Simply put this brace is two brackets and a bar that ties the rear ends of the two front a-arms together. The brackets bolt onto each of the inner rear bushing clamp bolts. Then there is a bar that connects to the two brackets via a bolt that acts as a pivot point. You cannot simply use a straight bar as there is a slight upward angle on the subframe and bushing clamps at the attachment point that would case a single piece to want to bend upwards into an arc. This is why this brace is made of three pieces, with pivots connecting them.

Required materials:
One 6” piece of 1½” square steel tubing (You could use aluminum, or stainless steel will be a good choice for those who live in areas where rust is a problem)
One 23” piece of 1” square steel tubing (Again, you could use aluminum, or stainless steel will be a good choice for those who live in areas where rust is a problem)
Two 3” long ⅜” diameter bolts with 1¾” of unthreaded body (this sizing isn’t critical, it’s just what I used, but make sure that you have sufficient unthreaded length to extend all the way through the 1 ½” tube so that you do not have threads in shear.)
Two ⅜” locknuts
Eight large ⅜” washers
Eight medium ⅜” washers
Some spray paint of your choice (make sure it’s durable as it’ll take a beating being under the car, something like Tremclad rust paint should do the trick)

What to do:
First we’ll start off by making the brackets that bolt onto the front a-arms rear bushing clamp. Take the 1½” square tubing and cut two pieces 2¾” long. Drill a 13/32” hole ½” from the end, centered on the tube. This will be where the tubing bolts to the suspension. On the opposite side of the tube from the hole measure 1” from the end and cut a section of the tube off at an angle to allow a socket to fit so that the suspension bolt may be inserted into the hole and tightened with a socket. On the opposite end of the bar, ¾” away from the end of the tube and centered in the tube, drill a ⅜” hole through both sides of the tubing on the sides that are 90 degrees to the existing hole. This will be the hole that the bolt goes through that attaches the bracket to the bar that connects each side together, so make sure it’s straight. We are now finished fabricating the bracket.

Now we’ll make the bar that will connect the brackets together to make the brace. Take the 23” long 1” square tubing and measure ¾” from one end centered in the tube and drill a ⅜” hole through the tube.

Now you have a choice, you can do the same for the other end (holes 22" apart) and hope that your car has the same dimensions as mine, or you can bolt the one end of the bar onto the bracket using the hardware listed above by placing two large washers on either side of the 1½” bar and two of the medium washers between the 1½” bar and the 1” bar, on both sides of the 1” bar and then bolting it together with the bolt and locknut. Then you must bolt the bar onto the car and bolt the other bracket onto the opposite side, making sure that the bar is in the bracket. Then take the ⅜” drill bit, insert it into the hole in the bracket and press it against the bar and move the bar up and down to make a mark on the bar. This will now show you where you need to drill the hole for the other bolt to pass through. Unbolt it all and drill the hole in the bar, then bolt the bracket onto the bar in the same way that the other side is done and then you can bolt it all onto the car to check the fitment.

Once you are happy with the fitment you can now take it back off, disassemble it and paint it so it won’t rust. Once it’s been painted then you can re-assemble it and re-install it. You are now done and you’ve spent less than $15 and only a few hours building for yourself what would have cost you $100-150 to buy commercially.

I don’t have any pictures of it now, as my parents took the digital camera with them on vacation, but when they return I’ll try to get some shots of it both on and off the car.

For the small amounts amount of time, effort and cost involved in making this it's definetly worth it. You will be rewarded with many advantages such as improved steering feel, better turn in, better stability under braking, better cornering stability, and an overall stiffer front end due the fact that the a-arm pivots can now no longer move relative to one another. This is a great compliment to a strut tower bar, because with both of these, all of the suspension attachment points will be braced against each other.

wow, i need pics....

Very interesting. Definitely need pics though. It's very hard to visualize what you are saying, at least for me it is :) Looking forward to the pictures.

pics!

My parents get back with the camera next monday (the 8th of August). It'll probably be the next weekend before I can get pics of it.

I made some quick sketches of it in paint, hopefully this will help clear up the confusion.

definitely PICs

I Managed to get some pics of it fully assembled off the car, on car pics will come in a few weeks. Here are some pics of the whole thing, close ups will follow.

Here are the close ups. Notice how I plugged the end of the bar with swooden blocks and some silicone sealant. This will hopefully help prevent rust from developing in the bar. It's not pretty, but hey, it's on the bottom of the car and no one will ever see it, so who cares!

Id like to see pics of it installed....as I cant for the life of me picture where this thing gets installed at!

Thanks.

I like it! Easy to do with limited tools too. If you buy 1/8" wall 1 1/4" tubing (more difficult, but not impossible to find) you can eliminate the washers between the tubes. Since I own a welder I'll bolt my end tubes in place and weld the long center section into the ends. In fact I'll probably cut open one side of the outer tube so I can better weld the sections together.

In the picture below on the right, it would go across the top of the X, where the rear A-arm mounts are.

http://www.corksport.com/store/image...er_Bar_Set.jpg

hmm...thanks for the pics.

Ive never heard/seen anything like this before.

It really helps that much, huh?

You wouldn't be able to use 1 1/4" tubing as when installed there's a slight angle between the brackets and the center section, this is why I didn't just use a single bar, and why I used the 1" bar instead of 1 1/4" (the place where I got the metal had some of both). The brackets end up being pointed upwards towards the center of the car.

As for getting the metal, most welding and fabricating shops will sell you the small amounts of metal required for a few bucks.

It's not a handling miracle, but it helps, it's worth the $10 I spent on it, that's for sure!

Whenever I am able to get pics of it installed I'll post them.

pics installed please ^_^?

Pretty good job.

I enjoy lower arm bars that replace the mounts completely (like the Mazdapseed lower arm stiffener bar) rather than bolt to it, but still great job. Reminds me of the Cusco one.

I would have preferred to get a Mazdaspeed one, or do a similiar thing. But I don't have acess to a welder, and I can't swing that kind of money now, so this is what I came up with. If you have a welder, have acess to a welder, or are willing to have the suspension apart for a while while a pro does the work you could weld tabs onto the stock mounts and bolt a bar in between them. This will give you a slightly stiffer mounting for the bar. I don't think it'll be very much more effective as I can't see that the mounts themselves actually flex that much.

I managed to borrow a digital camera and I got some pics of it installed. There's close ups of the bracket, mounting bolt, a pic showing that this doesn't affect ground clearance as the oil pan is lower, and a pic showing the clearance between the bar and the downpipe.

Here's the last pic.

Nice write-up. If you boxed in the ends, it would make it stronger, that way you could utilize all four sides instead of just the two where the bolt goes through.Good bar for cheap
though!

An alternative to this bar is the Himni Racing lower arm bar. It's only about $50. Their on Ebay and I think they have a website. It's allot stronger, doesn't have pivoting joints, the center piece is aluminum, and the ends are thick steel with good welds. It's also adjustable for beaten up fc chassis, so there's no problems with fitting.

The only other bar I like is the Mazdaspeed. Just so expensive though.

which kind is the red one on the first page??

AUTO-EXE is the red one.

It's also quite expensive. Cork Sport has it listed for a mere $515.

Wow, nice. This is going on my list of weekend projects for sure!

What he said.